1. Field of the Invention
This invention relates to systems and processes that are used to manufacture hollow containers such as plastic beverage bottles from preforms. More specifically, this invention relates to an improved process and apparatus for transferring preforms within such a system to an oven or other system component.
2. Description of the Related Technology
Conventional systems for blowmolding preforms in a facility for manufacturing, for example, PET bottles generally include at least one preform heat treating station in which the preforms are heated to a temperature at which they can be reshaped, a station or subsystem for transferring the preforms to the heat treatment station, and a blowmolding station for molding the preforms into the shape of a mold that corresponds to the outer shape of the container that is to be produced.
Typically, the station or subsystem for transferring the preforms to the heat treatment station includes an oven starwheel that is designed to grip the individual preforms in pockets that are disposed about its periphery and transport the preforms in a circular path that corresponds to the circumference of the star wheel. Such conventional systems may also include a preform feed wheel that is positioned to pick the preforms out of a linear array and feed the preforms into the star wheel. The feed wheel and starwheel in such systems are synchronized for common movement by means of a chain or belt linkage, or by continuously engaged gearing. While such systems are generally effective, they tend to be expensive because of the cost of providing and maintaining the mechanical connection between the star wheel and the feed wheel, and also tend to be susceptible to jamming, particularly at the input end of the feed wheel, where the feed wheel is designed to receive the individual preforms from the linear array while continuously rotating.
It may be concluded, then, that there is a need for an improved system and process for transferring preforms to a heat treatment station in a blowmolding manufacturing facility that is less expensive to deploy and maintain than conventional systems, and that is also less susceptible to mechanical malfunction.